A wide variety of genital tract diseases of female domestic animals are known to produce signifcant morbidity and mortality. The cervix, vagnia, uterus are prime sites for the formation and development of numerous purulent genital tract diseases, such as pyometra, mucometra, metritis, endometritis, vaginitis, and cervicitis.
The diagnosis and treatment of each of the above named diseases is readily accomplished by a veterinarian ordinarily skilled in the treatment of domestic animals. Such a diagonis and treatment proceeds from a recognition of the known characteristics of each of these diseases and the employment of one of the known modalities of treatment. For example, ovariohysterectomy is employed in pyometra and mucometra, and chronic cases of metritis. However, this use of surgery, aside from the obvious destruction of the animal's reproductive potential, is not indicated in many cases for economic reasons, thus necessitating the sacrifice or other disposition of the animal. In other genital tract diseases, such as acute episodes of metritis, endometritis, cervicitis and vaginitis, treatment with antibiotics is often successfully, although for severe or chronic cases surgical treatment is required if the animal is to be restored to good health.
Both naturally occuring prostaglandins and prostaglandin analogs are known in the art. The naturally occuring prostaglandins have the prostanoic acid skelton, and carbon atom numbering illustrated by formula I: ##STR1## See Bergstrom, et al. Pharmacol. Rev. 20, 1 (1968) and references cited therein. For example, prostaglandin E.sub.2 (PGE.sub.2) exhibits the following structure: ##STR2##
The term prostaglandin analog herein refers to those compounds structurally related to the prostaglandins (in that they exhibit a cyclopentane, or adjacently homologous cycloalkane, ring and a pair of side chains attached to adjacent carbon atoms of the ring) which retain characteristic biological properties of the prostaglandins. See Bergstrom, cited above. Various structural modifications of the prostaglandins are known to produce useful prostaglandin analogs. For example, the replacement of the carboxy with a hydroxymethyl or aminomethyl is known; substitution of a methyl, ethyl, or fluoro for a hydrogen at, for example, C-2 or C-16, and replacement of a methylene by an oxa or thia at, for example C-5 is known. Further, partially deoxygenated prostaglandins are known to be useful prostaglandin analogs. Accordingly, 9-deoxy, 11-deoxy, and 15-deoxy-prostaglandins are known. Further, there are known prostaglanin analogs wherein the double bonds of, for example, PGF.sub.2.alpha. are shifted, e.g., cis-4,5-didehydro-PGF.sub.1.alpha., or replaced by triple bonds, e.g., 13,14-didehydro-PGF.sub.2.alpha.. Finally there are known bicyclic large ringed lactones wherein the C-1 carboxyl forms a lactone with a ring or side chain hydroxyl, at C-9, C-11, or C-15.
As used herein, the term prostaglandin-type compound refers to any prostaglandin or prostaglandin-analog.
The use of prostaglandins in domestic animals, especially in regulation of the reproductive cycle, is known in the art. See, for example Lauderdale, J. W., J. Anim. Sci. 35:426 (1972); Lauderdale, J. W. et al., J. Anim. Sci. 38:964 (1974); Miller, R. A., et al., J. Anim. Sci. 41:369 (1975); and Hafez, Ed., Reproduction of Farm Animals, 3rd. Edition, Lea and Febizer, (1974), pp. 432-436 and references cited therein which describe method of administration and the effect of subcutaneous or intramuscular injection of the tris(hydroxymethyl)amino-methane (THAM) salt of PGF.sub.2.alpha. on the estrus cycle of domestic animals and discuss the desirability and usefulness of such activity.